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Number of results: 7
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Abstract

This paper discusses the contribution of linguistics to theology, taking the specific example of L.-M. Chauvet’s thought. First, the critique of language as a tool is analyzed. According to Chauvet, language can no longer be considered as a tool, but as a mediation, understood as a “matrix” or environment ( milieu). Linguistic mediation is thus explained from the conceptual perspective of symbol and symbolic order: human subjectivity is inseparable from language, and language has a symbolic structure. Theological reflection follows the concept of mediation and symbol as an important anthropological fact. Faith, then, involves rejecting the illusion of direct contact with God and accepting the mediation of the Church and the sacraments as a process of “accepting ourselves” as children of God and accepting one another in Christ as brothers.
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Authors and Affiliations

Paweł OFM Sambor
1
ORCID: ORCID

  1. Pontificia Università Antonianum, Roma
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Abstract

The dedicated gravity satellite missions, in particular the GRACE (Gravity Recovery and Climate Experiment) mission launched in 2002, provide unique data for studying temporal variations of mass distribution in the Earth’s system, and thereby, the geometry and the gravity field changes of the Earth. The main objective of this contribution is to estimate physical height (e.g. the orthometric/normal height) changes over Central Europe using GRACE satellite mission data as well as to analyse them and model over the selected study area. Physical height changes were estimated from temporal variations of height anomalies and vertical displacements of the Earth surface being determined over the investigated area. The release 5 (RL05) GRACE-based global geopotential models as well as load Love numbers from the Preliminary Reference Earth Model (PREM) were used as input data. Analysis of the estimated physical height changes and their modelling were performed using two methods: the seasonal decomposition method and the PCA/ EOF (Principal Component Analysis/Empirical Orthogonal Function) method and the differences obtained were discussed. The main findings reveal that physical height changes over the selected study area reach up to 22.8 mm. The obtained physical height changes can be modelled with an accuracy of 1.4 mm using the seasonal decomposition method.
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Authors and Affiliations

Małgorzata Szelachowska
Jan Krynski
Walyeldeen Godah
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Abstract

The GRACE-based model GGM02S is a global gravity model expressed in spherical harmonics. As the model is a global solution, a certain smoothing of the available gravity field information is unavoidable. For regional geoid determination the irregularities of residual gravity field should be included. The paper presents the global GRACE gravity field solution, regionally improved by adding a residual field, which is represented by radial base functions. The GRACE observations over the territory of Poland are analysed and a regionally improved GRACE geoid from this data is derived. This improved regional geoid is compared with the Polish quasigeoid and differences between the global and regionally improved GRACE GGM02S solutions are discussed. The study shows that the error of the official GRACE GGM02s solution was reduced by 50% due 10 regional refinement.
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Authors and Affiliations

Antoni Markus
Andrzej Borkowski
Wolfgang Keller
Magdalena Owczarek
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Abstract

Marine geoid modelling in the Atlantic coastal region of Argentina is problematic. Firstly, because of the insufficient amount of available shipborne gravity data, which renders a purely gravimetric solution not feasible. Secondly, because of the very strong ocean currents, that affect the quality of satellite altimetry data, so that a purely altimetrie model is too noisy, even after low-pass filtering the Sea Surface Heights (SSHs) to remove (part of) the influence of the oceanographic signals. Thus, the recommended solution is to employ a combination method and the use of all the available gravity and altimetry data together. This is a suitable solution since (i) combination methods such as least squares collocation and Input Output System Theory (!OST) inherently low-pass filter and weigh the data, and (ii) will make use of the altimetrie heights to fill the gaps of the shipborne gravity data. Following this idea, purely altimetrie, gravimetric and combined (using the !OST method) marine geoid models have been estimated for Argentina, employing all available shipborne gravity data, satellite altimetry SSHs and the latest Earth Gravity Models (EGMs) developed from CHAMP and GRACE missions. The new EGMs are especially useful to assess the quality of the new geoid models, especially against EGM96, which was used in an older ERSl-only solution for the same area. From the comparison of the estimated geoid models with respect to stacked TOPEX/Poseidon SSHs, the authors found that the altimetrie model provides the best agreement while the combined one improves the accuracy (I a) of the gravimetric solution.
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Authors and Affiliations

Claudia Tocho
Georgios S. Vergos
Michael G. Sideris
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Abstract

Gravity Recovery and Climate Experiment (GRACE) mission data is widely used in various fields of science. GRACE explored changes of the gravity field regularly from April 2002 to June 2017. In the following research, we examine variance of signal contained in two different formats of GRACE data: standard spherical harmonics and mass concentration blocks (so-called “mascons”) solutions, both provided in the most recent releases. For spherical harmonics-based solution, we use monthly gravity field solutions provided up to degree and order (d/o) 96 by three different computing centers, i.e. the NASA’s Jet Propulsion Laboratory (JPL), the German Research Center for Geosciences (GFZ) and the Center for Space Research (CSR). For the mass concentration blocks, we use values of total water storage provided by the CSR, JPL and the Goddard Space Flight Center (GSFC) computing centers, which we convert to spherical harmonic coefficients up to d/o 96. We show that using the anisotropic DDK3 filter to smooth the north-south stripes present in total wate storage obtained from standard spherical harmonics solution leaves more information than common isotropic Gaussian filter. In the case of mascons, GSFC solution contains much more information than the CSR and JPL releases, relevant for corresponding d/o. Differences in variance of signal arise from different background models as well as various shape and size of mascons used during processing of GRACE observations.

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Authors and Affiliations

Artur Lenczuk
ORCID: ORCID
Grzegorz Leszczuk
Anna Klos
ORCID: ORCID
Janusz Bogusz
ORCID: ORCID
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Abstract

For over two decades, an essential information about global monthly gravity variations is provided by the GRACE mission and its successor, the GRACE Follow-On (GRACE-FO) mission. The temporal variations in gravity field from GRACE/GRACEFO are determined based on the measurement of distance changes between two identical satellites using microwave ranging instruments. This process is carried out by various processing centers, which adopt different processing strategies and background models. This causes discrepancies in the resulting gravity fields.We address this problem by determining a monthly homogenous GRACE-FO gravity field solutions from June 2018 to November 2022 as provided by different processing centers included in the Science Data System (SDS) project, i.e. the Center for Space Research (CSR), the German Research Center for Geosciences (GFZ) and the Jet Propulsion Laboratory (JPL). We test three different weighting schemes. We show that for the last 4 years, at least 65% of continental areas are characterized by water decrease. We show that proposed merged solutions contain more signal information than individual ones based on the square root of the degree variance values.We note that the largest signal differences between individual and combined solutions occur for sectoral coefficients up to degree 40, and for zonal coefficients, the signal differences are twice as small.We also present that the differences in the spherical harmonic coefficients cause differences in global and local equivalent water height (EWH) changes. For example, the proposed merged solutions reduce root mean square scatter ofEWHby 5–15% comparing to individual solutions.
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Authors and Affiliations

Artur Lenczuk
1
ORCID: ORCID
Anna Klos
1
ORCID: ORCID
Janusz Bogusz
1
ORCID: ORCID

  1. Military University of Technology, Warsaw, Poland
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Abstract

This study discusses how to model the noise in a Gravity Recovery and Climate Experiment (GRACE)-Mascon derived Equivalent Water Thicknesses (EWT) time-series. GRACE has provided unique information for monitoring variations in EWT of continents in regional or basin scale since 2002. To analyze a GRACE EWT time-series, a standard harmonic regression model is used, but usually assuming white noise-only stochastic model. However, like almost all kinds of geodetic time-series, it has been shown that the GRACE EWT time-series contains temporal correlations causing colored noise in the data. As well known in geodetic modelling studies, neglecting these correlations leads to underestimating the uncertainties, and so misinterpreting the significancy of the parameter estimates such as trend rate, amplitudes of signals etc. In this study, autoregressive noise modeling, which has some advantageous compared to the approaches and methods frequently applied in geodetic studies, is considered for GRACE EWT time series. For this aim, three important basins, namely theYangtze, Murray–Darling and Amazon basins have been examined. Among some applied autoregressive models, the ARMA(1,1) model is obtained as the best-fitting noise model for analyzing the EWT changes in each basin. The obtained results are discussed in terms of forecasting, significancy and consistency with GRACE-FO mission.
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Authors and Affiliations

Ozge Gunes
1
ORCID: ORCID
Cuneyt Aydin
1
ORCID: ORCID

  1. Yildiz Technical University, Istanbul, Turkey

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